1. Field of the Invention
The invention is directed to a safety binding for a boot holding device in which the heel can be lifted, in which the boot is held in the binding at its front sole part by means of a clamping device which can be actuated at will, the binding being constructed in two parts and having a base part which is fixed with respect to the ski and a release part which is detachable from the base part during overloading by means of rotation relative to the base part and is held at the base part in the operating position by means of a release mechanism.
2. Background Art
Bindings of this type can be used for long-distance skiing, tour skiing, skiing corresponding to the recently revived telemark style, and for ski jumping. In these ski disciplines the skier must be able to lift the heel from the ski. While safety bindings for long-distance skiing, for example, are already known, no such safety bindings exist for ski jumping. This sometimes results in severe injuries in falls from th ski jump.
In a known binding of the type mentioned in alone (DE-A-33 10 739), the sole of the boot which is lengthened toward the front is fixed by means of a plug-in pin at the upper binding part which is constructed as a plate. This upper binding part which is constructed as a plate extends to the vicinity of the boot heel and is supported so as to be swivelable approximately in the center by means of a trunnion which is fixed with respect to the ski. The plate has an elongated hole through which the headless trunnion engages, so that the plate can free itself from the ski together with the shoe after the releasing process. The plate is secured against lifting in the rear area by a bracket which overlaps the plate and is supported toward the front against a spring-mounted release pin which is arranged on the ski very far in front of the shoe because of the necessary holding device for the sole which projects forward.
This construction results in various disadvantages. A significant disadvantage consists in that the release part which is detachable from the ski by means of rotation must be mechanism, which includes a spring-mounted pin, requires that the release part be supported at a certain distance in the lateral direction. In the known binding, the lateral support is effected by the rotating trunnion on which the plate is supported so as to be rotatable. This relatively large dimensioning of the plate, which is compulsory, results in an additional weight load on the one hand and in the risk of ice formation between the plate and the ski on the other hand, which substantially impairs the releasing process. Another substantial disadvantage consists in that the release pin and the locking opening in the plate are located very far in front of the boot, resulting in large differences in the releasing behavior depending on whether the boot rests on the ski or the heel of the boot is lifted. In order to counter this disadvantage a variant of the known binding discussed in the beginning provides a twofold arrangement of release parts. That is, an additional release system in the form of a shorter plate is provided on the release plate, both of them cooperating with spring-mounted locking balls. This construction not only adds considerable weight, but also results in a disproportionately higher construction cost because of the two release systems. Moreover, it is not possible to free the boot from the ski in this construction since the release parts are connected with the ski in a fixed manner.